The present invention is generally directed to water filters used to filter chemicals and water-laden particulates from potable water. More particularly, the present invention is directed to a self-contained replaceable water filter cartridge assembly having its own carbon block water filter pressure vessel and inlet and outlet ports which are provided with one-way check valves. The water filter cartridge of the present invention is designed to be disposable and easily replaced by the user. The one-way check valves disposed within the inlet and outlet ports of the cartridge of the present invention are designed to prevent reflux of contaminated water into the inlet water supply and prevent leakage of water from the inlet and outlet ports of the cartridge during replacement.
Current domestic water treatment systems for the treatment of potable water generally employ a cylindrical pressure vessel having a removable base. The base is provided with inlet and outlet ports on the bottom thereof and the top end of the base is adapted with a threaded male member to threadingly receive a generally cylindrical water filter thereon. With the filter elements secured upon the base, the threaded male member is in fluid communication with both the outlet port on the bottom of the base and the filter element itself. When the base is secured to the shell portion of the pressure vessel, the inlet port is in communication with an area defined by the space between the water filter element and the inside of the pressure vessel housing shell.
In operation, the inlet port is plumbed to a faucet or similar device which, when opened, allows water to flow into the pressure vessel between the filter element and the inside of the pressure vessel shell wherein water is forced through the filter element via pressure. The carbon filter element generally has a non-porous plastic cap on the end located distally from the base and, proximate to the base, has a non-porous cap having female threads disposed therein adapted to threadingly attach to the threaded male member of the base. However, the filter, having a hollow core lined with a porous plastic material, will allow water to flow therethrough under line pressure through the porous plastic in the hollow core and continue its flow out through the outlet port. The outlet port of the filter cartridge is generally either plumbed to a spigot from which the user can draw water for consumption or to a second stage of water treatment such as an ultraviolet light chamber for sterilizing bacteria and other organisms not arrested during the filtering stage.
Domestic water filter systems periodically require maintenance, particularly for the purpose of replacing the filter element. In order for the consumer to access the filter element for replacement, the consumer must first shut off the water supply and disconnect the pressure vessel from its inlet and outlet port plumbing fitments. Removal and replacement of the filter often requires an assortment of tools, both for the plumbing fitments from the inlet and outlet ports of the pressure vessel and to open the pressure vessel for access to the filter. Other systems provide easier access to the water filter by utilizing quick-release fitments and by adapting the pressure vessel to be opened by hand. In any case, if the filter had been in use prior to disassembly of the pressure vessel, both filtered and non-filtered water will remain inside the filter and pressure vessel during maintenance. Once the inlet and outlet port plumbing fitments are disconnected from the pressure vessel, filtered water will spill out of the pressure vessel outlet. While this is messy, and even dangerous, particularly when any electronic elements are incorporated into the water treatment system, even more critical is the fact that unfiltered water will spill from the pressure vessel inlet port, thereby risking contamination of components of the water treatment system designed to only handle filtered water.